1. Field
This invention relates to apparatus and methods for separating a carrier fluid from solids suspended within that fluid. More particularly, the invention is directed to apparatus and methods of processing which utilize gravity to effectuate a liquid/solids separation.
2. State of the art
Various clarifier systems for use in separating carrier fluids from suspended solids are well known in the art. These systems typically include a vessel having an inlet and an outlet. The inlet and outlet are positioned to establish a flow path for a stream of fluid mixture introduced into the vessel. A separation unit is oriented within that flow path to intercept the stream of mixture and separate the carrier fluid from the solids suspended within the fluid. The carrier fluid is thereafter channeled off into one receiving area while the solids are directed to another.
U.S. Pat. No. 3,951,818 (Bosnjak) discloses a clarifier of the gravity separation type. Simply stated, this clarifier includes a vertical upright channel defined by a pair of separation elements. Each of the separation elements includes a vertical plate which is intersected at spaced intervals along its height by outwardly extending flow directioning plates. The directioning plates intersect the vertical plate at an acute angle; ie. the directioning plates are not arranged parallel to a horizontal plane.
The vertical plates each define a predetermined plurality of sized orifi, positioned proximate each intersection of the vertical plate with a flow directioning plate; ie. proximate an apex. Each of the orifi communicates with the vertical channel thereby establishing a pathway from the body of fluid mixture to the vertical channel.
The Bosnjak separation elements are suspended within a receiving vessel by two upright supports which are spacedly positioned one from another. The supports include a plurality of outwardly extending rods. The apex of each separation element, as formed by the intersection of the vertical plate with a directioning plate, is placed over a respective support rod and thereafter held in position by the action of the rod against the respective apex.
In operation, clarifiers of the kind typified by the Bosnjak structure have experienced difficulty in operation. Conventionally, the vertical plates have not been held in a sealed relationship with upright supports. These upright supports form the sides of the respective compartments defined by the association of the vertical plate, directioning plates and supports. As a result of the unsealed relationship, short circuiting of the separation process occurs. Specifically, unclarified mixture may bypass the gravity separation action of the compartments by flowing around the vertical plates directly to the vertical channel. This short circuiting action results in the clarified carrier fluid being contaminated by an infusion of unclarified fluid mixture. This contamination imposes a practical limitation on the separation efficiency of the clarifier; ie. on the concentration of clarified carrier fluid obtainable.
The requirement of a vertical channel makes clarifiers of the Bosnjak construction relatively large spatially. Considering that clarifiers may be installed in spatially restricted environments, such as in mines, the spatial requirements of this clarifier construction may prove disadvantageous.
U.S. Pat. No. 4,544,487 (Bosnjak) discloses a clarifier system composed of back-to-back positioned separation elements. Each element includes a vertical plate intersected at spaced intervals by outwardly extending flow directional plates similar to those disclosed in U.S. Pat. No. 3,951,818. The vertical plate and flow directioning plates form a series of apexes similar to the construction described above. The later structure differs from the former in that the apexes include a curved wall which substantially confines the area extant between each intersection of the vertical plate and a directioning plate thereby forming an open-ended horizontally oriented pipe. This horizontal channel functionally substitutes for the vertical channel of the former construction as a means of withdrawing clarified carrier fluid from the clarifier. As shown in FIG. 6B of U.S. Pat. No. 4,544,487, the vertical plate/flow directioning plates assembly appears to be fixedly mounted on the side supports to form a fully integrated separation unit.
While clarifier configurations of the type disclosed in U.S. Pat. No. 4,544,487 remedy the short circuiting complications of prior clarifiers and reduce somewhat the clarifier's spatial requirements, such clarifiers engender a different problem. Specifically, clarifiers must often be installed in spatially confined environments. Often, the access way to the installation site is sufficiently narrow that clarifier components having dimensions, such as those of the separation units described in U.S. Pat. No. 4,544,487, may not pass through that access way. Resultingly, the user must disassemble or remove preexisting structure to permit the passage of the clarifier components.
In view of the disclosed clarifiers, there exists a need for a clarifier system which circumvents the possibility of the fluid mixture short circuiting the clarifier process. Further, this clarifier should be suitable for conveyance through spatially restricted access ways as well as be adapted for installation in spatially confined environments.